Torque Arm Length Calibration

Wire Cloth and Sieve Measurement

Parameter / Equipment

Range

CMC Uncertainty (±)

Wire Cloth and Sieves

(0.020 to 12.5) mm

4.4 μm

Calibration and Measurement Capability (CMC) is the smallest uncertainty of measurement that a
laboratory can achieve within its scope of accreditation when performing more or less routine
calibrations of nearly ideal measurement standards or nearly ideal measuring equipment.

Calibration
and Measurement Capabilities represent expanded uncertainties expressed at approximately the 95 %
level of confidence, usually using a coverage factor of k = 2. The actual measurement uncertainty of a
specific calibration performed by the laboratory may be greater than the CMC due to the behavior of
the customer’s device and to influences from the circumstances of the specific calibration.

Please note the actual measurement uncertainties achievable on a customer's site can normally be
expected to be larger than the CMC found on the A2LA Scope. Allowance must be made for aspects
such as the environment at the place of calibration and for other possible adverse effects such as those
caused by transportation of the calibration equipment. The usual allowance for the actual uncertainty
introduced by the item being calibrated, (e.g. resolution) must also be considered and this, on its own,
could result in the actual measurement uncertainty achievable on a customer’s site being larger than the
CMC.